Rails - Jul 2006 - Community request - can someone show me REST?

I mentioned this in another thread, but I''ve got a formal request now.
 After reading tons of stuff about REST, I don''t really get it.  I
need to see an example.

I''d like someone to write up an example blog app with these
requirements
- RESTful using the simply_restful plugin (or edge rails)
- allows posting of comments to articles
- has categories for posts

No need for authentication.

I have two questions that would be answered by that example app.  The
first is just how to use simply_restful in the first place.  I also
wonder how you''re supposed to use REST when the only thing interesting
about a particular resource is its associations.  i.e. does
http://myapp/category/1 just display a list of posts in that category?

This may go unnoticed, I''m not sure.  I already tried to start this on
my own so I could figure it out...but I got stuck very early on.  I''d
find that example app very illuminating.  If someone with the knowhow
could take the time to do this, I''d be very appreciate, as would many
others I''m sure.

Pat

Pat Maddox <pergesu@...> writes:
> I''d like someone to write up an example blog app with these
requirements
> - RESTful using the simply_restful plugin (or edge rails)
> - allows posting of comments to articles
> - has categories for posts
Here you go:

  http://randomoracle.com/stuff/RestBlog.tar.gz

(It uses tags instead of categories. Categories are *so* Web 1.0!)

You''ll have to untar it, then:

- rake rails:freeze:edge
- rake migrate
- script/server

and it should just work (assuming you have sqlite3 installed). No tests, sorry.
If anything doesn''t work,  or you want an explanation, just ask (but CC
me,
as I don''t read this group).
> I also wonder how you''re supposed to use REST when the only thing
interesting
> about a particular resource is its associations.  i.e. does
> http://myapp/category/1 just display a list of posts in that category?
In this case, /tags/1 will do just that. But you can also go to /tags to get a
list of all tags, or destroy tag 1 by sending DELETE to /tags/1. In a
different implementation, you might also have /tags/new, or /tags;search.

Regards,
Alisdair McDiarmid
TrackChair
http://www.trackchair.info/

On 8/1/06, Alisdair McDiarmid <alisdair@randomoracle.org>
wrote:
> Pat Maddox <pergesu@...> writes:
>
> > I''d like someone to write up an example blog app with these
requirements
> > - RESTful using the simply_restful plugin (or edge rails)
> > - allows posting of comments to articles
> > - has categories for posts
>
> Here you go:
>
>   http://randomoracle.com/stuff/RestBlog.tar.gz
Hi Alisdair,

I found this VERY informative, so thanks for doing it.  The only
question I have is regarding the nested resources.

  map.resources :articles do |article|
    article.resources :comments
  end

I don''t understand why you need to do that.  I also don''t
understand
why it needs to be done in that manner, rather than simply doing
map.resources :comments.

Pat

On 8/2/06, Pat Maddox <pergesu@gmail.com> wrote:
>
> On 8/1/06, Alisdair McDiarmid <alisdair@randomoracle.org> wrote:
> > Pat Maddox <pergesu@...> writes:
> >
> > > I''d like someone to write up an example blog app with
these
> requirements
> > > - RESTful using the simply_restful plugin (or edge rails)
> > > - allows posting of comments to articles
> > > - has categories for posts
> >
> > Here you go:
> >
> >   http://randomoracle.com/stuff/RestBlog.tar.gz
>
> Hi Alisdair,
>
> I found this VERY informative, so thanks for doing it.  The only
> question I have is regarding the nested resources.
>
>   map.resources :articles do |article|
>     article.resources :comments
>   end
>
> I don''t understand why you need to do that.  I also don''t
understand
> why it needs to be done in that manner, rather than simply doing
> map.resources :comments.
>
> Pat
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
I have another question regarding this one.  How does link_to and form_for
work with the REST principles?  Is there anything special that you need to
do or is it all done behind the scenes by the routes?
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://wrath.rubyonrails.org/pipermail/rails/attachments/20060802/37f46ab7/attachment.html

link_to and form_for takes the :method option.

Example:

		<%= link_to ''Delete'', { :action =>
''destroy'', :method => :delete },
															:method => :delete,
															:confirm => ''Are you sure? There is NO
undo!'' %>

form_for is similar.  See the documentation for more details.

Hope this helps,
Zack

On 8/1/06, Daniel N <has.sox@gmail.com> wrote:
>
>
> On 8/2/06, Pat Maddox <pergesu@gmail.com> wrote:
> > On 8/1/06, Alisdair McDiarmid <alisdair@randomoracle.org> wrote:
> > > Pat Maddox <pergesu@...> writes:
> > >
> > > > I''d like someone to write up an example blog app
with these
> requirements
> > > > - RESTful using the simply_restful plugin (or edge rails)
> > > > - allows posting of comments to articles
> > > > - has categories for posts
> > >
> > > Here you go:
> > >
> > >   http://randomoracle.com/stuff/RestBlog.tar.gz
> >
> > Hi Alisdair,
> >
> > I found this VERY informative, so thanks for doing it.  The only
> > question I have is regarding the nested resources.
> >
> >   map.resources :articles do |article|
> >     article.resources :comments
> >   end
> >
> > I don''t understand why you need to do that.  I also
don''t understand
> > why it needs to be done in that manner, rather than simply doing
> > map.resources :comments.
> >
> > Pat
> > _______________________________________________
> > Rails mailing list
> > Rails@lists.rubyonrails.org
> > http://lists.rubyonrails.org/mailman/listinfo/rails
> >
>
>  I have another question regarding this one.  How does link_to and form_for
> work with the REST principles?  Is there anything special that you need to
> do or is it all done behind the scenes by the routes?
>
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
>
>

Pat,
  You need to do this to allow simply_restful to build the correct
url.  using the example given, comments are only relevant when tied to
an article.

So a url like:
comments/3 doesn''t make any sense
You need nesting to get
articles/3/comments/

Hope this helps,
Zack

On 8/1/06, Pat Maddox <pergesu@gmail.com> wrote:
> On 8/1/06, Alisdair McDiarmid <alisdair@randomoracle.org> wrote:
> > Pat Maddox <pergesu@...> writes:
> >
> > > I''d like someone to write up an example blog app with
these requirements
> > > - RESTful using the simply_restful plugin (or edge rails)
> > > - allows posting of comments to articles
> > > - has categories for posts
> >
> > Here you go:
> >
> >   http://randomoracle.com/stuff/RestBlog.tar.gz
>
> Hi Alisdair,
>
> I found this VERY informative, so thanks for doing it.  The only
> question I have is regarding the nested resources.
>
>   map.resources :articles do |article|
>     article.resources :comments
>   end
>
> I don''t understand why you need to do that.  I also don''t
understand
> why it needs to be done in that manner, rather than simply doing
> map.resources :comments.
>
> Pat
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

> So a url like:
> comments/3 doesn''t make any sense
> You need nesting to get
> articles/3/comments/
/comments/3 makes sense.  But this nesting builds in a certain layer
of security.  Instead of Comment.find(params[:id]) you do:

@post = Post.find(params[:post_id])
@comment = @post.comments.find(params[:id])

This way you can never grab a comment in another post, for example.

-- 
Rick Olson
http://techno-weenie.net

On 8/1/06, Rick Olson <technoweenie@gmail.com>
wrote:
> > So a url like:
> > comments/3 doesn''t make any sense
> > You need nesting to get
> > articles/3/comments/
>
> /comments/3 makes sense.  But this nesting builds in a certain layer
> of security.  Instead of Comment.find(params[:id]) you do:
>
> @post = Post.find(params[:post_id])
> @comment = @post.comments.find(params[:id])
>
> This way you can never grab a comment in another post, for example.
Where is this post_id coming from?

Basically I''m wondering now that we have
  map.resources :articles do |article|
   article.resources :comments
 end

When/where would I actually use it?

Pat

Pat,

You use the routes that simply_restful creates.  link_to, form_for,
url_for, etc. use the routes created by map.resources.  SR also
creates named routes.  Use Rick''s excellent routing navigator to see
them all:

http://weblog.techno-weenie.net/2006/6/19/new-plugin-routing-navigator

Zack

On 8/1/06, Pat Maddox <pergesu@gmail.com> wrote:
> On 8/1/06, Rick Olson <technoweenie@gmail.com> wrote:
> > > So a url like:
> > > comments/3 doesn''t make any sense
> > > You need nesting to get
> > > articles/3/comments/
> >
> > /comments/3 makes sense.  But this nesting builds in a certain layer
> > of security.  Instead of Comment.find(params[:id]) you do:
> >
> > @post = Post.find(params[:post_id])
> > @comment = @post.comments.find(params[:id])
> >
> > This way you can never grab a comment in another post, for example.
>
> Where is this post_id coming from?
>
> Basically I''m wondering now that we have
>   map.resources :articles do |article|
>    article.resources :comments
>  end
>
> When/where would I actually use it?
>
> Pat
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

On 8/2/06, Rick Olson <technoweenie@gmail.com>
wrote:
>
> > So a url like:
> > comments/3 doesn''t make any sense
> > You need nesting to get
> > articles/3/comments/
>
> /comments/3 makes sense.  But this nesting builds in a certain layer
> of security.  Instead of Comment.find(params[:id]) you do:
>
> @post = Post.find(params[:post_id])
> @comment = @post.comments.find(params[:id])

Hi Rick,

thanks for the insights!!

IMHO it makes sense to use urls like /articles/3/comments in the views as
well. But I don''t get the railish way of constructing something like
/articles/3/comments/new or /articles/3/comments/1;edit with link_to yet.

As I wrote in another post something like <%= link_to ''Add
Comment'',
:controller => ''articles'', :action =>
"#{article_id}/comments/new" %> does
what I want from a technical perspective, but results in an encoded url (
http://localhost:3002/articles/1%2Fcomments%2Fnew<http://localhost:3002/articles/1/comments/new>)
which doesn''t look as elegant as the whole approach... There''s
got to
be a
railish way to construct this url unencoded. I just don''t get it.

I would love the readibility of urls like this and as you wrote they
introduce a level of security as well.

Cheers,
Jan
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://wrath.rubyonrails.org/pipermail/rails/attachments/20060802/6ba09af6/attachment.html

Daniel ----- wrote:
> On 8/2/06, Pat Maddox <pergesu@gmail.com> wrote:
>> > Here you go:
>>   end
>>
> I have another question regarding this one.  How does link_to and 
> form_for
> work with the REST principles?  Is there anything special that you need 
> to
> do or is it all done behind the scenes by the routes?
When you have:

map.resource :widgets

in your routes.rb, there are a bunch of named urls created for you to 
use.

widgets_url =>              /widgets (previously /widgets/list)
widget_url(@widget) =>      /widgets/1
new_widget_url =>           /widgets/new
edit_widget_url(@widget) => /widgets/1;edit

-- 
Posted via http://www.ruby-forum.com/.

On 8/2/06, Alisdair McDiarmid <alisdair@randomoracle.org>
wrote:
> On 8/2/06, Pat Maddox <pergesu@gmail.com> wrote:
> > The only question I have is regarding the nested resources.
> >
> >   map.resources :articles do |article|
> >     article.resources :comments
> >   end
> >
> > I don''t understand why you need to do that.  I also
don''t understand
> > why it needs to be done in that manner, rather than simply doing
> > map.resources :comments.
>
> By the way, the routing automatically creates the :article_id parameter
> based on the class name of the enclosing route, which is a bit magical
> (but then this is Rails, so you should be used to that :-)
To clarify, do you just mean that comment_url(1, 2) will result in
/articles/1/comments/2 and set params[:article_id] for you?

Also, for anyone else that''s having some trouble with this,
I''ve found
that playing with the routes in console is very illuminating.  Load up
console and do
app.articles_url
app.article_url(article)
app.comment_url(article, comment)

of course you have to have created an article and comment object first
to pass in.  After messing with that for a bit though, the automatic
routes made a lot more sense to me.

Pat

On 8/2/06, Pat Maddox <pergesu@gmail.com> wrote:
> On 8/2/06, Alisdair McDiarmid <alisdair@randomoracle.org> wrote:
> > By the way, the routing automatically creates the :article_id
parameter
> > based on the class name of the enclosing route, which is a bit magical
> > (but then this is Rails, so you should be used to that :-)
>
> To clarify, do you just mean that comment_url(1, 2) will result in
> /articles/1/comments/2 and set params[:article_id] for you?
Yes, exactly that, and also set params[:id] (to 2).

But also, comment_url(@article, @article.comments.first) will do
something similar. How your model converts to route parameters is up
to you: the default is the primary key, but you can override to_param
if you want, and return a different (unique) value. This is useful if
you don''t want ids in URLs.

Regards,
Alisdair